Narcolepsy is a chronic sleep disorder that involves affects the body’s ability to regulate sleepiness and wakefulness. It is characterized by periods of excessive daytime sleepiness, hallucinations, sleep paralysis, and short involuntary sleep episodes.
It is very common for people with narcolepsy to sleep during the day since the line between being awake and being asleep is blurred. Many people affected by narcolepsy also experience fatigue and sudden paralysis of the muscles, a condition known as cataplexy.
This condition causes a sudden loss in muscle strength, and this leads to weakness of the arms, legs or trunk, or a slack jaw. People with narcolepsy also experience vivid nightmares.
There is no known cause for narcolepsy. It may be triggered by genetic factors, medical conditions, trauma, infections, psychological stress. Narcolepsy has also been associated with a lack of hypocretin, a chemical produced by the hypothalamus in the brain.
It is responsible for alerting the systems of the brain, keeping us awake, and regulating sleep-wake cycles. Without this chemical, a person may find it difficult to remain awake.
Diagnosis of narcolepsy is dependent on symptoms and sleep studies to rule out possible conditions that could cause excessive daytime sleeping such as alcohol consumption, sleep apnea, anemia, depression, and heart failure.
Although there is no cure for the disease, certain lifestyle changes and medications can help to manage the disease.
Narcolepsy often begins in childhood, and it affects both males and females equally. Delayed treatment of the condition increases the risk of road accidents and falls.
Types of Narcolepsy
Narcolepsy with Cataplexy
This type of narcolepsy occurs in addition to cataplexy. Cataplexy involves the weakness and sudden loss of control in the muscles of the face, arms, legs, or torso.
This causes the person to have a slack jaw, to slur words, or to slump over. Cataplexy is commonly mistaken as a seizure, although they are not the same thing. During a cataplexic episode, the person is fully conscious.
An episode can last up to two minutes and is usually triggered by a strong emotion such as anger or excitement.
Narcolepsy without Cataplexy
A narcoleptic person without cataplexy has all the symptoms of narcolepsy, including extreme daytime sleepiness, hallucinations, sleep paralysis, and disrupted night time sleep, but without episodes of sudden weakness and loss of control of the muscles that is triggered by strong emotions.
This type of narcolepsy is less severe than narcolepsy with cataplexy.
Causes of Narcolepsy
The exact cause of narcolepsy is unknown. However, it may be an autoimmune, genetic disorder that causes a deficiency of hypocretin (orexin), a chemical that controls the sleep-wake cycle.
This chemical is a neurotransmitter produced in the hypothalamus of the brain and controls sleepiness and wakefulness by acting on different groups of nerve cells in the brain.
Hypocretin is necessary for keeping us awake. When not available, the brain allows rapid eye movement (REM) sleep phenomenon to interrupt normal periods of wakefulness randomly. This results in excessive daytime sleepiness and lack of sleep at night.
Narcoleptic patients with cataplexy typically have low levels of hypocretin, while those without cataplexy do not. Other possible causes of narcolepsy include tumors, head trauma, and other diseases that could affect the brain.
Signs and Symptoms of Narcolepsy
Excessive daytime sleepiness (EDS)
This is the major symptom of narcolepsy. EDS is a continuous feeling of sleepiness throughout the day, with an inclination to drift into sleep, usually at inappropriate times.
These are known as sleep attacks and can result in poor concentration, fatigue, the inability to remember things, depression, and even fatal accidents.
This is the sudden loss of muscle strength in the face, neck, arms, legs, knees, or torso. The effects can be mild like a head drop, or severe like a complete loss of muscle control and collapse.
Episodes of cataplexy are often triggered by strong emotions like anger, laughter, or shock.
These are vivid and often frightening sensations or experiences that may appear real but are created by the mind. This symptom is caused by the blend of sleepiness and wakefulness that occurs during REM sleep.
Sleep paralysis is the body’s inability to speak or move while waking up or falling asleep. Sleep paralysis episodes generally last from a few seconds to a few minutes. At the end of an episode, the person recovers the ability to move and speak.
Persistent daytime sleepiness can occur as a result of a number of conditions. People who experience excessive sleepiness should seek medical attention to determine the exact cause.
Narcolepsy is often mistaken for a psychological condition like restless leg syndrome and sleep apnea, and the symptoms are often misdiagnosed.
Diagnosis of the condition would require a complete medical and sleep history, sleep studies, and physical exams. Some of these tests include:
- The Epworth Sleepiness Scale (ESS), a simple questionnaire that is used to determine how likely you are to sleep in different circumstances.
- Lumbar puncture used to collect the cerebrospinal fluid to measure hypocretin levels.
- Home monitoring systems to keep track of how and when you fall asleep. This device is worn like a wristwatch and may be used along with a sleep diary.
- Polysomnogram (PSG) testing involving the use of electrodes to monitor brain activity, heart rate, breathing, eye movement, and muscle movement while asleep.
- A multiple sleep latency test (MSLT) which is used to determine the length of time it takes to fall asleep during the day.
Narcolepsy is a lifelong condition that has no cure. Treatment options can only be used to manage symptoms and improve daytime functioning.
Medications that can be used to treat narcoleptic symptoms include:
- Antidepressants to reduce cataplexy, sleep paralysis, and hallucinations. These medications, however, can have unpleasant side effects, like constipation, cottonmouth, and urinary retention.
- Stimulants such as armodafinil (Nuvigil), methylphenidate (Ritalin), and modafinil (Provigil) may be used to improve wakefulness.
- Selective serotonin reuptake inhibitors (SSRIs) like Prozac helps to regulate sleep and improve mood.
- Serotonin-norepinephrine reuptake inhibitors (SNRIs) such as Effexor helps in the treatment of sleep paralysis, hallucinations, and cataplexy.
Living with Narcolepsy
Certain lifestyle changes would be necessary to manage narcolepsy symptoms and improve general well being. These include:
- Keep a consistent sleep schedule.
- Establish relaxing bedtime rituals.
- Do not go to bed unless you are sleepy.
- Set a bedtime that will allow at least 7 hours of sleep.
- Get out of bed if you do not fall asleep after 20 minutes.
- Beds should be used for only sleep and sex.
- Your room should be quiet and relaxing.
- Minimize exposure to light in the evenings.
- Avoid large meals before bedtime. Eat a light, healthy snack if you are hungry at night.
- Reduce fluid intake before bedtime.
- Exercise and stretch regularly and maintain a healthy diet.
- Avoid alcohol.
- Avoid consuming caffeine in the late afternoon or evening.